Electrical starting and ignition system for internal-combustion engines



April 9, 1946.

R. E. SLAYTON ELECTRICAL STARTING AND IGNITION SYSTEM FOR INTERNAL-COMBUSTION ENGINES Filed Jan. 22, 1945 INVENTOR.

- ATTORNEY Patented Apr.'-9, 1946 ELECTRICAL STARTING AND IGNITIOfi SYSTEM FOR INTERNAL-COMBUSTION ENGINES Robert E. Slayton, Elmira, N. Y.', assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application January 22, 1943, Serial No. 413,23; I I

4 Claims. (Cl. 123-179) The present invention relates to electrical starting and ignition systems for internal combustion engines and more particularly to an arrangement which is operative in cold weather to Fig. 3 is an enlarged detail of the thermostatic snap switch controlling the ignition circuit, the

thermostat being shown in its warm condition.

In Fig. l of the drawing there isdllustrated a starting circuit for an. internal combustion endelay closure of the ignition circuit of an engine gine not illustrated, including a battery I groundso that the engine is initially cranked with out ed at 2 and connectedby a lead 3 to a magnetic ignition, starting switch 4. Switch 4 is connected by a lead When a very cold internal combustion engine 5 to the starting motor Sm which is grounded at is to be started, it has often been found to be ad- B to complete the starting circuit. Switch 4 is vantageous to crank the engine 'for a brief period provided with an actuating coil 1 grounded at 8 of time prior to closure of the ignition circuit. and connected by a lead 9 through a starter con- This insures that all the cylinders will be well trol switch II to the battery lead 3. charged with a rich fuel mixture before any of An ignition circuit for the engine is provided them are ignited. It also tends to dilute the oil comprising an ignition switch I2 connected by a film on the cylinder walls, which reduces the vis-' lead i3 to the battery lead 3 and by a, lead I4 cosity of the oil and thereby increases the crankto a thermostatic snap switch indicated genering speed. When the ignition circuit is then ally by numeral l5. Thermostatic switch i5 is closed, the cylinders are all in condition to fire connected by a lead It to the primary I! of the in sequence and sustain the rotation of the enignition coil l8 which is grounded through timer gine without interruption. The occurrence of soi9 in the usual manner, the secondary 2| of the called false starts" requiring repeated operation coil. being connected through distributor 22 to the of the cranking mechanism, is thus obviated. spark plugs 23 of the engine.

It is an object of the present invention to pro- According to the present invention, the thervide a novel electrical system for internal commostatic switch It comprises a flexible switch bustion engines which is arranged to delay 4310- 25 blade 26 anchored at 25 and having at its free sure of the ignition circuit when the engine is end a double contact 28 which is arranged to enchilled. gage alternatively a contact 21 on the ignition It is another object to provide such a device in lead It or a fixed contact 28 grounded at 29. which the ignition circuit incorporates a ther- Thermostatic means for actuating the switch mostatic switch which opens at low temperatures. 30 blade is provided in the form of a bi-metallic It is another object to provide such a device instrip or bar 3| also mounted at one end on the eluding electrical heating means for the thermofixed anchorage 25 and having its free end 0011- a und r the c ntr l of the operator. nected to the free end of the switch blade 24.

It is another object to provide suchadevice ina through a spring toggle arrangement so as to cluding heating means for the thermostat conconstitutes. snap action device. trolled by the i nit n wi h As shown in Fig. 3, this is accomplished by It is f rther o ject to provide such a device forming the switch blade 24 as a bifurcated including heating means for the thermostat conmember, and mounting the thermostatic strip 3| trolled by the starting switch. so that its free end may pass through the space It is another object to provide such a device in between the furcations of the switch blade. which the thermostat is warmed by heat from Spring member 32 is then mounted under slight the engine during the operation of the engine. initial compression between the free end of the Further objects and advantages will be appa-rthermostatic strip and the cross bar 33 of the ent from the following description taken in conswitch blade. Preferably bearing cups 34 and 35 nection with the accompanying drawing in are employed to form seats for the ends of the, which: spring 32 and constitute rocker bearings with the Fig. 1 is a semi-diagrammati illustration of an adjacent surfaces of the thermostatic strip and electrical system incorporating a preferred emswitch blade. bodiment of the invention showing the parts in The thermostatic strip 31 is so mounted and idle and cold position; constituted that when its temperature is below Fig. 2 is a similar view of a second embodiment a predetermined minimum, such, for example, as of the invention in which the thermostatic switch 10 F., it will occupy the position illustrated in is controlled concurrentl with the starting Fig. 1, and will consequently hold the switch switch; and blade 24 in position to cause the contact 26 to engage the grounded contact 28. When the strip spring will snap the contact 26 away from the grounded contact 28 and into engagement with 1 the ignition contact 21, as illustrated in Fig. 3.

ignition switch I? by the operator accordingly has no immediate eil'ect. Closure of the,starting control switch Ii by the otor simultaneously Means under the control of the ignition switch ii for heating the thermostatic strip 3! to cause closure of the ignition circuit after a predetermined time is provided in the form of a heater coil 88 connected at one end to the ignition circuit lead it and at the other end by a lead 81 to the-anchored end of the switch blade 2d. The

coil 86 has a comparatively low resistance and is so designed that when it is grounded through contacts 26, 28, it will heat up rapidly and cause the thermostatic strip 8! to open contacts 28, 28, and close the ignition circuit contacts 28, 2? after a few seconds. The resistance of the heater coil is so low that it does not sheet the operation of the ignition system, the slight amount of heat generated by the coil during the operation of the engine being merely sumcient to keep the thermostatic strip slightly warm.

In the operation of this embodiment of the invention, when the engine is chilled so that the thermostatic contacts are in the positions illustrated in Flg. 1, closure or the starter control switch H and the ignition switch i2 by the oper ator causes the magnetic starting switch s to close, and at the same time completes the heating energizes the magnetic starting switch coil l and the thermostat heating coil 86' thus causing the starting motor to crank the engine, and after a predetermined time interval causing the thermostatic switch to close the contacts 25, 2t and complete the ignition circuit, whereby the engine is rendered self-operative. When the starter control switch ii is opened by the operator, the heating coil 86' is tie-energized, but the temperature of the thermostatic strip M is maintained suficiently high to prevent opening the circuit through coil 38 and contacts 26, 28. The

engine is thereupon cranked for a few revolutions while the ignition circuit is held open by the thermostatic-switch i5. After a few seconds, the thermostatic strip 3! is sumciently heated by the coil 38 to bend up, moving the toggle spring 32 past its dead center position so that it snaps the switch blade 2d down and closes contacts 26,

- 21, completing the ignition circuit. Since all the tained by heat conduction from the engine dur-- ing the operation thereof. For this purpose the thermostatic switch I! is'mounted on the engine exhaust manifold 38, and the heater coil 36' is connected at one end by a lead 39 to the starting switch coil lead 9. The other end of the heater coil 36' is grounded as indicated at Al to complete the heating circuit. The ignition lead i4 is connected directly to the switch blade'24 to complete the ignition circuit through contacts 26, 21 to the ignition coil I 8.

ignition contacts 2%, 27 by heat conducted from the engine.

Although but two embodiments of the invention have been shown and described in detail, it will be understood that other embodiments are possible and various changes'may he made in the design and arrangement of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In an electrical system for internal combustion engines an ignition circuit including an ignition coil and a switch for controlling the energization of the coil, thermostatic means for opening the switch at 'a predetermined low temperature and manually controlled electrical heating means for the thermostatic means.

2. In an electrical system for internal combustion enginesan ignition circuit including an ignition coil, and means for controlling the energization thereof including a manually operable ignition switch and a thermostatic switch arranged to be opened at a predetermined low temperature, and electrical heating means for the thermostat controlled by said ignition switch.

3. In an electrical system for internal combustion engines an ignition circuit including an ignition coil and means for controlling the ener- I gization thereof including a switch, thermostatic means for opening the switch at a predetermined low temperature, a starting system for the engine including a startercontrol switch and heating means for the thermostat controlled by said starter control switch.

4. In an electrical system for internal combustion engines a snap switch having two sets of contacts arranged to be closed alternatively, thermostatic controlling means for the switch, an ignition circuit for the engine including one of said sets of contacts and a heating circuit for the thermostat including the other set of contacts, the heating circuit contacts being closed when the thermostat is chilled, and the ignition circuit contacts being closed when the thermostat is warm.

ROBERT E. SLAY'I'ON. 

